1. Field of the Invention
The present invention relates to a rack transporting apparatus for transporting a sample rack holding sample containers, and a sample processing apparatus in which the rack transporting apparatus is used.
2. Description of the Related Art
Japanese Patent Publication No. 2008-32652 discloses a conventional transporting apparatus for transporting a sample rack to a sample processing unit which processes a sample.
Japanese Patent Publication No. 2008-32652 discloses a transporting apparatus disposed along an arrangement direction of a plurality of analyzing units disposed in a linear arrangement, wherein the transporting apparatus transports a sample rack, delivered by a rack delivering unit, to a sample suctioning position of the analyzing units and then finally send back the sample rack to a rack collecting unit disposed on the same side of the rack delivering unit relative to the analyzing units. The transporting apparatus is equipped with an overtake lane where a sample rack for urgent sample and a sample rack for interrupt sample are transported, an ordinary lane where a sample rack for general sample is transported, and a return lane where a sample rack from which a sample has been suctioned is transported back to a rack collecting unit, wherein the ordinary lane is provided with sample suctioning positions of the analyzing units. The transporting apparatus further has a lane changer which changes the lane to be selected for transporting the sample rack. The lane changer which is slidable in a direction orthogonal to a transport direction of the sample rack can transfer the sample rack from the overtake lane to the ordinary lane and from the ordinary lane to the return lane.
According to the transporting apparatus recited in Japanese Patent Publication No. 2008-32652, however, the sample rack on the overtake lane has to stay there until the lane changer is ready to transfer the sample rack on the overtake lane to the ordinary lane when the transfer of the sample rack to the ordinary lane is prevented by, for example, the presence of any other sample rack on the ordinary lane. In the event that the sample rack on the ordinary lane cannot be transferred to the return lane by, for example, the presence of any other sample rack on the return lane, the sample rack on the ordinary lane is kept there until the sample rack on the ordinary lane can be transferred to the return lane by the lane changer. Therefore, when trying to transfer any subsequent rack using the overtake lane or the ordinary lane during the occurrence of these events, the transport of the subsequent rack on the overtake lane or the ordinary lane is temporarily stopped. Thus, it fails to smoothly transfer the subsequent sample rack using the overtake lane or the ordinary lane.